Wet chemical preparation method for ceramic separation membrane

Abstract

The invention relates to a wet chemical preparation method for a ceramic separation membrane. The method provided by the invention comprises the following steps: adding aluminum oxide particles with the particle size of 30-70 micrometers and an aqueous solution which is prepared by dissolving aluminum nitrate, titanium alkoxide and lanthanum nitrate or yttrium nitrate in advance into a sufficientquantity of ammonia water; adjusting the pH value to 8-10; after fully reacting at 65-90 DEG C, precipitating, washing, aging and drying; presintering at 500-800 DEG C to obtain the aluminum oxide particles coated with nano oxides; after mixing the aluminum oxide particles coated with the nano oxides and an organic molding assistant, kneading to form plastic pug; extruding to form a green body ofa support body; sintering the green body for 0.5-5 hours at 1450-1700 DEG C to form the support body; and coating a membrane and sintering to obtain a ceramic separation membrane product. The preparation method provided by the invention has the advantages that a nano material is utilized to coat Al2O3 powder, thus spherical particles with high sintering activity is obtained, a molding formula andprocess in production procedures can be simplified and the complicated courses of drying the green body and turning over the green body can be avoided.

Description

technical field [0001] The invention relates to a method for preparing a ceramic separation membrane, in particular to a method for preparing a ceramic separation membrane through a wet chemical process. Background technique [0002] The most industrial application value of the ceramic membrane is the tubular multi-channel ceramic membrane. The industrial production method is generally to use larger particles of alumina powder to produce a tubular multi-channel support with a larger pore size, and then in the support body. Dip-coat one or several layers of alumina with smaller particles in the channel, form a membrane layer with smaller pores after sintering, and finally obtain an asymmetric tubular multi-channel ceramic membrane. [0003] The key technology and main cost of the ceramic membrane lies in the manufacture of the support body. At present, there are two main manufacturing processes for the support body. The first one is to mix a certain amount of submicron alumin...

AI Technical Summary

Problems solved by technology

[0003] The key technology and main cost of the ceramic membrane lies in the manufacture of the support body. At present, there are two main manufacturing processes for the support body. The first one is to mix a certain amount of submicron alumina powder into the tens of micron alumina powder. The support body uses submicron alumina powder to provide sintering activity and binds large particles of alumina powder. The advantage of this method is that the purity of alumina in the support body is very high, basically above 99.5%, and the manufactured support body can be It is suitable for most environments with high temperature and high acid and alkali corrosion, but its disadvantages are also obvious. Submicron alumina powder blocks the gaps of tens of micron alumina powder, resulting in a decrease in porosity and a decrease in filtration flux. At the same time, timely Doped with submicron alumina powder, the sintering temperature is still very high, basically above 1800°C, resulting in high cost

The second method is to dope some low-temperature sintering aids in the manufacture of the support body, which can greatly reduce the sintering temperature, reduce costs, and also have a higher porosity, but because the sintering effect is low-temperature sintering aids , so the acid and alkali resistance is greatly reduced, and the scope of use is therefore limited